Solder pump



y 1 J. M. CALEHUFF ETAL 2,986,108

SOLDER PUMP Filed March 10, 1958 4 Sheets-Sheet 1 INVENTORS JAMES M: CALEHUFF F g 1 WILLIAM L. REITER STANLEY L. SKOWRONSKI BY Wa ATTORNEY May 30, 1961 J. M. CALEHUFF EIAL 2,985,108

SOLDER PUMP Filed March 10, 1958 4 Sheets-Sheet 2 INVENTORS ATTORNEY United States Patent SOLDER PUMP James M. Calehuif, Montoursville, William L. Reiter,

South Williamsport, and Stanley L. Skowronski, Williamsport, Pa., assignors, by mesne assignments, to Sylvania Electric Products Inc., Wilmington, Del., a corporation of Delaware Filed Manltl, 19,58, Ser. No. 720,199

7 Claims. (Cl. 113-93) The invention relates to apparatus for pumping liquids of the character which congeals under normal atmospheric temperatures and to pumping of liquids to provide a clean scum free surface at anarea of discharge of the liquid.

It is an object of the inventionto provide an apparatus which will pump liquids subject to congealing at normal atmospheric temperatures without possibility of breaking parts during operation of the apparatus should the liquid become congealed.

It is a further object-of the invention to provide for fluid pressure operation of parts with a pressure sufficiently small to preventjbreakage due to-jamming of parts, as for example by.;improper engagement of a soldering pot element with parts being soldered.

It is another object: of the invention to. force liquids subject. to surface scum-, oxidation or the-like out of an orifice in scum free condition.

Specifically, it.is an object of the invention to provide anapparatus for pumpingrnolten solder and to cause the solder to flow fountain like out of the top-of' a vertical pipe, the solder thus flowingoutbeing ledto a pool from below. the surface ofwhich vthemolten solder, is fed to the fountain.

These and, other objects will become apparent upon considering the following'specificationwhen taken in conjunction with the accompanying drawing inwhichz' Fig. 1 is a front elevationwitha portionin section taken along the line 11 of Fig. 3..

Fig. 2 is a vertical mid section taken through Fig. l, with parts broken away to expose other portions.

Fig. 3is a plan view of thcapparatus of the. invention.

Fig. 4 is an enlarged view of thesolder pot shown in the upper portion of Fig. 1.

Fig. 5 is a plan view of a bracket which. supports the solder pot.

Fig. 6 is atop view 'ofanelongated mounting frame,

Fig. 7 is a top of a combined pump and fountain angled bracket.

Fig. 8'isa section. throughv the bracket taken on the line 8-8 of Fig. 7.

Referringto the drawingsrwith greater particularity, at 10- there is-indicated an elongated mounting frame. This frame comprises a generally rectangular portion 12. having ways 13 to provide aslideway, two rearwardly extending webs 14 anda-mounting-back plate 16 integral, with the webs. The back plate isprovided with a horizontal locat-. ing rib or key, 20 for fitting in a groove in a vertical face ofa supporting base fragmentarily indicated at 21, and is further provided with a pair of ifianges 22, each withhorizontally elongated apertures 24 for receptionofbolts 26 threaded into the'base frame. The rectangular portion of the mounting-frame isformed with a web portion 28at its upper end, the web portion :being longitudinally slotted at its lower end, as indicated at 30, toaccommodatethe movementjof a lever 32operated by a.cam.33. Below the web portion, the bracket frame is. hollowfromfront Patented May 30, 1961 ice bottom of the frame and this member is apertured at 36.

Within the aperture 36 is fixed the threaded bottom the cylinder.

and engaging opposite faces of the member 35. The piston rod enters an air cylinder 42 located in the area 34, with the piston .onthe rod normally at the upper end of Air pressure is supplied to the cylinder via an inlet pipe 44 adapted to be fiexibly'connected to any source of constant air pressure, as an-air ballast tank, so that the cylinder is normally resiliently urged to move upwardly in the hollow of the frame while the piston is held immovable. To limit the upward motion of thecylinder, the same is provided with a stop, plate 46 suitably bolted .to the lower end of the cylinder, said plate being adapted to engage, in the upward travel of the cylinder,- an adjustable set screw 47 threaded into a cross bar 48 fastened to enlargements 50 on the sides of the frame 10.

To limitthe-downward motion of parts, as well be explained, the top of the mounting frame may be provided with stop buttons 51.

Slidable between the ways 13 is a generally rectangular slide 52, recessedlat its lower end, as indicated at 54, to form a lost motion connection between the lever 32 and the slide, the slide being'further providedat its lower end with a cross bore 56. A pin 58 couples the slide with the cylinder. by reason of passing through the bore 56 and through a registeringopening inan'ear 59 fastened to the top ofrcylinder 42. The lowerend. of theslot 54 is narrowedto prevent too free lateral movement of the car on the cylinder. The. lower end of the slide is pro: vided with a second cross bore 60, above the bore 56 to accommodate a pin 62,, Onthis pin is rotatably mounted an antifriction roller 64. to, be engaged and thrust downwardly by the end of lever. 32 when the slide is to be forced downward against theair pressurewithin the cylinder 42. The slide is retained in, place within the slideway by two cover bars suitably bolted to the ways 13. v

To the upper end of the slide is bolted asolder pot supportingbracket 68. This bracket has aflat rectangular top face .70 provided with planed seats72, at eachof its corners. against which a solder pot enclosure 74' is boltedr The enclosure is a rectangular openjtop box made of suitable heat insulating material as for examplea hard sheetasbestos compound, with one side wall lower thanrthe others to make room for associated. machine parts. Within .the box is a solder pot 76, also-generally boxlike, with open top and outturned flanges 78 at its upper edges. The flanges are secured to thetop of the to rear asindicatedat 34. Across member 35 formsthe insulating enclosure by screws 80, the pot being thus spaced on all sides as well as the bottom from the insulating enclosure. At the lower side wall portion of the enclosure additional insulatingwalls 81,are provided to cover otherwise exposed portions of. the solder pot.

The bottom of the solder pot is formed with two circularbores 82 within which are seated two electrical heating elements 84 whose terminals 86 are connected in parallel by tie bars 87 and by electric wires 88 .with a source of electric, energy. Also formed in the bottom of the. solder pot is a drain port 90 normally closed by a ball valve 92 as of.steel, held against the port by a set screw 94. To prevent accidental removal of the set screw with, resulting undesired flow of solder out from the lateral opening, .a safety limiting screw with washer is provided. When the screw 94 is, backed out, the outer end thereof will engage the washer on the screw 95 and prevent complete withdrawal of the screw 94. When the screw 94 is loosened, after backing off the safety screw 95; the ball valve will be forced away from the port and the molten solder can then flow into a nipple .96. The nipple. may be closed 01f by a cap 98. When removed, the molten solder may flow into any suitablereceptacle held beneath the bracket 68. However this cap should be removed prior to loosening of the set screw 94.

The upper portion of the frame 10, besides having the flanges 22, has a pair of wings 100 with right angled channeled flanges 102 to which is fastened a gantry 104 comprised of upright supports 106 and a cross bar 108. The cross bar supports two solder pump pistons 110 via rods 111, as will be described in greater detail. These pistons cooperate with two solder pump cylinders 112, each cylinder being associated with a solder fountain 114. Each pair, comprising a pump cylinder and solder fountain, is supported by an angled bracket 116 having an upper horizontal flange 118 fixed to the solder pot, a vertical downwardly extending face 120 and a lower horizontal shelf 122, the bracket being reinforced by a vertical central web 124. Each bracket is further provided with a longitudinal bore 126 in the shelf portion leading to two recesses 128 and 130 having planed portions around the recesses as indicated at 132 and 134 for the seating of the solder pump assembly and solder fountain assembly, respectively. A plug 136 closes the horizontal bore after it has been formed.

Each pump cylinder has a flange portion 138 bolted to the seat 132 and an upright cylinder 140 having holes 142 spaced around the upper portion of the cylinder wall to allow solder from below the surface level of the solder in the solder pot to flow into the cylinder and fill the same on the down stroke of the solder pot. The lower end of the cylinder has a transverse wall 144 with a port 146 and ball valve 148 which may be of steel but preferably is of glass adapted to allow solder to flow into the bore 126 on the upstroke of the solder pot and pump cylinder and to close ofl the port on the downstroke or suction stroke of the pump cylinder. The piston also has at least one cross bore 150 below the surface level of the solder maintained in the pot, the bore communicating with a vertical passage 152 closed off by a steel or glass ball valve 154 free to move between the passage mouth and a retaining wire 156 across the bell shaped bottom of the piston. On the upstroke of the solder pot and solder pump cylinder, the port 142 will be shut off by the piston, and the ball valve 154 will close off the passageway 152. Trapped solder in the. pump cylinder will thus be forced into the bore 126 past the ball valve 148. On the downstroke of the solder pot, solder from below the surface will be sucked into the pump cylinder. The solder pot is moved downwardly against the action of the air pressure in cylinder 42 by reason of the cam 33 pivoting lever 32, the forward end of which bears against the roller 64 on the slide 52, which at its upper end carries the solder pot enclosure 74. The solder pot, it will be remembered, when released from the depressive action of lever 32 is limited in its upward movement by engagement of plate 46, movable with the cylinder, with the stop 47 on the frame 12 The piston 110 is suitably fastened to the piston rod 111 a higher elevation than it had before and now when the cylinder 1-12 rises to its maximum height as determined by the stop 47, there will still be a considerable amount of solder left in the cylinder 112. Therefore, a lesser charge of solder will have-been forced past the valve 148. The adjustment of the collar 162 with the collar 166 is for the purpose of maintaining the spring pressure of spring 158, as it had been before the readjustment of collar 166. A knob 168 is fastened to the upper end of the rod to lift the rod against the action of the spring for adjustment or cleaning of parts or for test pumping by hand when the solder pot is in raised position. For

' ease in assembly of parts, by relative lateral movement,

which passes freely through the cross bar 108 of the gantry 104. The rod is normally held against longitudinal movement by a stifi spring 158 tensioned between a bushing 160 reacting against a set screw retained collar 162 on the rod and a second bushing 164 reacting against the cross bar. A second collar 166 limits the expansion of the spring and determines the initial posi tion of the pump piston in the cylinder. By adjustment of the collars 162 and 166 along the rod, the quantity of solder pumped may be varied. For example, assume that in the position of the piston 110 in Fig. 1 a full upward movement of the cylinder 112 will force a full charge of solder past the ball valve 148, with the stop 47 so adjusted that the plate 46 will engage the stop when the bottom of the cylinder engages the piston 110. Now, if the collar 166 be loosened and the rod 111 be raised relative to the collar and the collar be again reset in its new position further down on the rod, the collar 166 will engage the bar 108 and maintain the piston at the cross bar 108 is notched as indicated at 169.

Each solder fountain comprises an outer solder feeder cylinder 170 and an inner rod 172, the space between the cylinder and rod affording a passageway for upflowing solder. The cylinder 170 includes a flange 174 bolted to the pump bracket 116 with the flange in engagewith the seat 134. The rod is integral with a vertically perforated collar 176 which rests on a shoulder 178 within the cylinder 170 and a set screw 180 holds the cylinder and rod locked together. The upper end of the cylinder is bevelled as indicated at 182 to promote free overflow of the solder and the rod 172 is centrally bored at 184 and provided with a bevelled edge 186 to facilitate entrance of a key on a tube base whose pins are being soldered to the leads of an electron tube.

- The apparatus is exemplified as being used for the purpose of soldering the pin leads of an electron tube to the base pins of a Bakelite socket at the bottom of said tube. In Fig. 2, in dotted lines, is shown a portion of a conveyor supporting a tube with the pins of the base as well as a central key portion directly above the solder fountain. Upon rise of the solder pot the key of the base will enter the hollow of the rod 172, while the pins to be soldered will enter a pool of solder being pumped up through the apertures in the collar 176. Excess solder will overflow the fountain and be returned to the pool of solder in the solder pot. Because the solder for application to the work to be soldered is drawn into the pump through ports 142 below the level of the solder in the pot and because a fresh supply of so obtained solder is pumped through the solder fountain, the solder is always scum free. The pressure in cylinder 42 is suificiently small so that should the solder be congealed and an attempt be made to operate the machine no damage could result. Further the spring 158 could yield thereby preventing damage to parts. Also since the pressure in cylinder 42 is small, but little force is required on the part of lever 32 to lower the cylinder.

What is claimed is:

l. A soldering mechanism comprising a base, a frame supported by said base, a vertically movable solder pot guided by theframe, a support above the solder pot carried by the frame, means on the frame and base for raising and lowering said pot; a pump and fountain in said pot, said pump and fountain comprising an angled bracket having an upper horizontal flange fixed to the solder pot, a lower horizontal shelf, a connecting web between said flange and shelf, a longitudinal bore in the shelf leading at each end into a recess in the shelf; a pump cylinder on the shelf communicating with one recess, a fountain cylinder mounted on the shelf connecting with said second recess; and a piston in said pump cylinder to pump liquid from said pump cylinder through said bore and into said fountain cylinder, said piston being connected with said support.

2. A soldering mechanism comprising a base, a frame mounted on said base, a movable solder pot guided for vertical movement by said frame, a fixed support mounted on said frame and extending over said pot, means on the base for raising and lowering the pot, a pump and fountain mounted in said pot withthe' pump feeding said fountain, said pump comprising a pump cylinder fixed with reference to the pot and a piston having a connection with said support, said connection comprising a piston rod passing through said support, spring means reacting between said support and piston rod to urge the piston into the cylinder, a stop on the rod engaging the support to limit the movement of the piston into the cylinder; and a hand knob on the end of the piston rod to facilitate manipulation of the piston.

3. A soldering mechanism comprisinng a base, a frame supported by said base, a solder pot movably supported by said frame, a pump cylinder and fountain fixed in said pot with the pump cylinder feeding the fountain, a support on the frame, said support having a gantry portion extending above and bridging the pot, a piston rod mounted in said gantry portion, a piston at the lower end of said piston rod cooperative with the pump cylinder, said frame extending downwardly below the solder pot and housing an air motor reacting between the pot and frame, said air motor being supplied with air under constant pressure to urge the pot upwardly, and positive means on the base reacting against the pot to lower the pot against the action of the air motor.

4. A soldering mechanism comprising a base, a frame supported by said base, a soldering pot movably supported by said frame, a fountain mounted in said pot, means communicating with the fountain to pump solder out of said fountain, and means to raise and lower the pot, said last means comprising said frame, a slide surmounted by said pot movable vertically in said frame, an air motor having a piston and cylinder with one of said parts of the motor connected with the frame and the other with the slide, means to supply the motor with air under constant pressure to raise the slide and soldering pot, and a cam operated lever on the base acting on the slide to lower the same against the force exerted by said air motor.

5. A soldering mechanism comprising a base, a frame supported by said base, a soldering pot movably supported by said frame, means supported by the base and frame for raising and lowering the pot, a pump cylinder and fountain fixedly mounted in said solder pot with outlet from the pump cylinder in communication with the fountain and the fountain extending above the level of the solder in the pot, a fixed support carried by the frame and extending above the pot, a piston rod with a piston fixed on the lower end thereof mounted in the support with the piston riding in the cylinder, an inlet to the cylinder below the level of the solder intermediate the height of the cylinder whereby substantially scum free solder may be supplied from said fountain, a one way valve in the outlet from the cylinder allowing solder to flow only in a direction toward the fountain, and means at a fixed elevation above the pot to support an article above the fountain for application thereto of flowing scum free solder as the pot is raised.

6. A soldering mechanism comprising a solder pot, a base, a frame mounted on said base, means on the frame resiliently supporting the weight of the solder pot and its contents, means on the base to move the pot downwardly against the force of the resilient means and to release the pot to the action of the resilient means, a pump cylinder fixed in the solder pot having a liquid intake below the level of the solder in the pot, a piston fixed relative to the frame and slidable in the cylinder, a fountain fixedly mounted in said solder pot in liquid communication with said cylinder and extending to a level above the solder in the pot whereby liquid solder may be pumped into said fountain in a substantially scum free condition upon relative movement of the piston and cylinder, and means on the frame at a fixed elevation above the pot to support an article above the fountain for application thereto of flowing scum free solder, as the pot rises under influence of said resilient means.

7. A soldering mechanism comprising a base, a frame supported by said base, a soldering pot movably supported by said frame, means supported by the base and frame for raising and lowering the pot, a pump cylinder and fountain fixedly mounted in said solder pot with outlet from the pump cylinder in communication with the fountain and the fountain extending above the level of the solder in the pot, a fixed support carried by the frame and extending above the pot, a piston rod with a piston fixed on the lower end thereof resiliently mounted in the support with the piston riding in the cylinder, an inlet to the cylinder below the level of the solder intermediate the height of the cylinder whereby substantially scum free solder may be supplied from said fountain, a one way valve in the outlet from the cylinder allowing solder to flow only in a direction toward the fountain, and means at a fixed elevation above the pot to support an article above the fountain for application thereto of flowing scum free solder as the pot is raised.

References Cited in the file of this patent UNITED STATES PATENTS 

